A wall wash is a type of light fixture, which is mounted to a ceiling and intended to direct light to the face of a wall near the fixture in a uniform manner to substantially eliminate shadows or other variations in intensity or shading across the illuminated surface of the wall. Ideally, light would be distributed evenly on the wall with the light directed close to the ceiling and a smooth transition down the face of the wall toward the floor. Such lighting, for example, may emphasize smoothness of the illuminated surface. Variations in surface texture, however, may disrupt the apparent uniformity by creating light and dark regions on the illuminated surface of the wall due to shadow effects of projecting features and the angle of light from the wall wash fixture.
A grazing application similarly uses a light fixture mounted to a ceiling intended to direct light to the face of a wall near the fixture. The grazing light fixture typically is mounted nearer the illuminated face of the wall and aimed to output light around an axis at a smaller angle relative to the wall face. Rather than emphasizing surface uniformity, such a grazing light fixture emphasizes texture by creating light and dark regions due to shadow effects of intentional design features of a textured surface on the face of the wall. Grazing, however, may also create undesired light and dark regions when portions of the surface that should be uniform are not uniform due to surface imperfections. A grazing light, however, may even be used to detect imperfections for corrections, for example, to allow a builder to detect and sand out or otherwise remove imperfections in a wall during construction.
Light fixtures for wall washing and grazing applications traditionally have relatively static light distributions specifically designed for the particular application. In either case, the fixture is mounted at a particular location and any adjustable components of the light fixture (e.g. relating to angle of emission toward the surface of the wall) are set during installation so as to provide the intended direction and range of angular distribution for the washing or grazing of the particular architectural panel. Once mounted and configured, the distribution remains unchanged unless a technician manually adjusts the fixture. Other than some minor manual adjustment, there is no practical technique to adjust the output distribution of light from the fixture, for example, to compensate for imperfections in the illuminated wall surface.